Search results for My First Linux Server, Part 2

Tutorial quote: In the previous two articles in this series, we examined some of the whys and whats of building Linux clusters. This article concludes our series by concentrating on the hows of cluster building. We've seen that a clustered approach to certain computing solutions can save lots of money in hardware and support costs. Now our job is to produce a method of building clusters that's repeatable and predictable—we don't want to give back our hard-won savings in project cost overruns.

Tutorial quote: The release of Red Hat Enterprise Linux 4 debuts the first commercially supported inclusion of Security-Enhanced Linux (SELinux). An installation of Red Hat's latest enterprise operating system has SELinux installed and enabled by default. In the past SELinux has been criticized for a lack of commercial support, many big sites were unable to use it due to the lack of support (Fedora Core 3 doesn't have the support that they require). Now in Red Hat Enterprise Linux 4, SELinux is a supported part of the OS, and such objections to the use of SELinux have gone away. SELinux is now widely regarded as being suitable for the largest sites.

Tutorial quote: Your network is growing in size and complexity. It's taking on a life of its own, spreading and growing and absorbing everything in its path. You're tearing your hair out trying to keep track, and your users have somehow discovered your secret phone number and are pestering you with endless questions and demands--where do I find this; I don't want to keep track of a dozen different passwords; nothing works like it should.

Of several possible solutions, consider two: 1) find a new hiding place, or 2) implement an LDAP server. While finding a new hiding place might sound ideal, it's an option we're going to have to save for a future article. This series will instead explain what LDAP is good for, detail how to build an LDAP server, and cover what you can do with it.

Tutorial quote: If you want to monitor and manage your Internet bandwidth, perhaps to make sure your ISP is not overbilling you, try vnStat, an open source, Linux-based application that gives you a clear picture of your bandwidth usage. This utility got the command-line options and also got the UI part which give the output in form of a graph and is simple to install and easy to use.

Tutorial quote: With the release of Microsoft's new Windows operating system (Vista), more and more people are looking for alternatives to Windows for various reasons. This tutorial is the first of a series of articles where I will show people who are willing to switch to Linux how they can set up a Linux desktop (Fedora Core 6 in this article) that fully replaces their Windows desktop, i.e. that has all software that people need to do the things they do on their Windows desktops. The advantages are clear: you get a secure system without DRM restrictions, and the best thing is: all software comes free of charge.

Tutorial quote: With the release of Microsoft's new Windows operating system (Vista), more and more people are looking for alternatives to Windows for various reasons. This tutorial is the second in a series of articles where I will show people who are willing to switch to Linux how they can set up a Linux desktop (Mandriva Free 2007 in this article) that fully replaces their Windows desktop, i.e. that has all software that people need to do the things they do on their Windows desktops. The advantages are clear: you get a secure system without DRM restrictions, and the best thing is: all software comes free of charge.

Tutorial quote: Have you heard about Xen virtualization and want to get some hands-on experience? Do you want to experiment with Linux clustering but only have a single computer to devote to the cause? If you answered yes to either of these questions, keep reading.

In this article, I briefly introduce the concepts of Xen virtualization and Linux clustering. From there, I show you how to set up multiple operating systems on a single computer using Xen and how to configure them for use with clustering. I should point out that a cluster implemented in this manner does not provide the computational power of multiple physical computers. It does, however, offer a way to prototype a cluster as well as provide a cost-effective development environment for cluster-based software. Even if you're not interested in clustering, this article gives you hands-on experience using Xen virtualization.

Tutorial quote: I have already covered how to execute commands on multiple Linux or UNIX servers via shell script. The disadvantage of script is commands do not run in parallel on all servers. However, several tools exist to automate this procedure in parallel. With the help of tool called tentakel, you run distributed command execution. It is a program for executing the same command on many hosts in parallel using ssh (it supports other methods too). Main advantage is you can create several sets of servers according requirements. For example webserver group, mail server group, home servers group etc. The command is executed in parallel on all servers in this group (time saving). By default, every result is printed to stdout (screen). The output format can be defined for each group.

Tutorial quote: The Internet has become a far more dangerous place than it was 20 years ago. Nowadays, Operating System and application security is an integral part of a server configuration and, while firewalls are very important, they are not the panacea.

This list of steps is intended as a guideline with a practical approach. We’ll try to provide a complete picture without getting into unnecesary details. This list won’t replace a good book on secure systems administration, but it will be useful as a quick guide.

Before we get started it’s worth to mention that security is not a status: it’s just a process. The correct initial setup of the server only provides a good start and helps you get half the way through. But you actually need to walk the other half of the road, by providing proper security vigilance, monitoring and updating.